diff options
Diffstat (limited to 'lib/libkvm/kvm_amd64.c')
-rw-r--r-- | lib/libkvm/kvm_amd64.c | 360 |
1 files changed, 360 insertions, 0 deletions
diff --git a/lib/libkvm/kvm_amd64.c b/lib/libkvm/kvm_amd64.c new file mode 100644 index 000000000000..acc7ac017a3c --- /dev/null +++ b/lib/libkvm/kvm_amd64.c @@ -0,0 +1,360 @@ +/*- + * SPDX-License-Identifier: BSD-3-Clause + * + * Copyright (c) 1989, 1992, 1993 + * The Regents of the University of California. All rights reserved. + * + * This code is derived from software developed by the Computer Systems + * Engineering group at Lawrence Berkeley Laboratory under DARPA contract + * BG 91-66 and contributed to Berkeley. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + + +/* + * AMD64 machine dependent routines for kvm. Hopefully, the forthcoming + * vm code will one day obsolete this module. + */ + +#include <sys/param.h> +#include <sys/endian.h> +#include <stdint.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <vm/vm.h> +#include <kvm.h> + +#include <limits.h> + +#include "kvm_private.h" +#include "kvm_amd64.h" + +struct vmstate { + size_t phnum; + GElf_Phdr *phdr; + amd64_pml4e_t *PML4; +}; + +/* + * Translate a physical memory address to a file-offset in the crash-dump. + */ +static size_t +_kvm_pa2off(kvm_t *kd, uint64_t pa, off_t *ofs) +{ + struct vmstate *vm = kd->vmst; + GElf_Phdr *p; + size_t n; + + if (kd->rawdump) { + *ofs = pa; + return (AMD64_PAGE_SIZE - (pa & AMD64_PAGE_MASK)); + } + + p = vm->phdr; + n = vm->phnum; + while (n && (pa < p->p_paddr || pa >= p->p_paddr + p->p_memsz)) + p++, n--; + if (n == 0) + return (0); + *ofs = (pa - p->p_paddr) + p->p_offset; + return (AMD64_PAGE_SIZE - (pa & AMD64_PAGE_MASK)); +} + +static void +_amd64_freevtop(kvm_t *kd) +{ + struct vmstate *vm = kd->vmst; + + if (vm->PML4) + free(vm->PML4); + free(vm->phdr); + free(vm); + kd->vmst = NULL; +} + +static int +_amd64_probe(kvm_t *kd) +{ + + return (_kvm_probe_elf_kernel(kd, ELFCLASS64, EM_X86_64) && + !_kvm_is_minidump(kd)); +} + +static int +_amd64_initvtop(kvm_t *kd) +{ + struct kvm_nlist nl[2]; + amd64_physaddr_t pa; + kvaddr_t kernbase, kernphys; + amd64_pml4e_t *PML4; + int found = 0; + + kd->vmst = (struct vmstate *)_kvm_malloc(kd, sizeof(*kd->vmst)); + if (kd->vmst == NULL) { + _kvm_err(kd, kd->program, "cannot allocate vm"); + return (-1); + } + kd->vmst->PML4 = 0; + + if (kd->rawdump == 0) { + if (_kvm_read_core_phdrs(kd, &kd->vmst->phnum, + &kd->vmst->phdr) == -1) + return (-1); + + for (size_t i = 0; i < kd->vmst->phnum; i++) { + if (kd->vmst->phdr[i].p_type == PT_DUMP_DELTA) { + /* Account for the 2M hole at KERNBASE. */ + kernphys = kd->vmst->phdr[i].p_paddr - + kd->vmst->phdr[i].p_align; + kernbase = kd->vmst->phdr[i].p_vaddr; + + found = 1; + break; + } + } + } + + if (found == 0) { + nl[0].n_name = "kernbase"; + nl[1].n_name = 0; + + if (kvm_nlist2(kd, nl) != 0) { + _kvm_err(kd, kd->program, "bad namelist - no kernbase"); + return (-1); + } + + nl[0].n_name = "kernphys"; + nl[1].n_name = 0; + + /* XXX + * Relocatable kernels can still be loaded at 2M. + */ + if (kvm_nlist2(kd, nl) != 1) { + _kvm_err(kd, kd->program, "cannot determine kernphys"); + return (-1); + } + + kernphys = 0; + kernbase = nl[0].n_value; + } + + nl[0].n_name = "KPML4phys"; + nl[1].n_name = 0; + + if (kvm_nlist2(kd, nl) != 0) { + _kvm_err(kd, kd->program, "bad namelist - no KPML4phys"); + return (-1); + } + if (kvm_read2(kd, (nl[0].n_value - kernbase + kernphys), &pa, + sizeof(pa)) != sizeof(pa)) { + _kvm_err(kd, kd->program, "cannot read KPML4phys"); + return (-1); + } + pa = le64toh(pa); + PML4 = _kvm_malloc(kd, AMD64_PAGE_SIZE); + if (PML4 == NULL) { + _kvm_err(kd, kd->program, "cannot allocate PML4"); + return (-1); + } + if (kvm_read2(kd, pa, PML4, AMD64_PAGE_SIZE) != AMD64_PAGE_SIZE) { + _kvm_err(kd, kd->program, "cannot read KPML4phys"); + free(PML4); + return (-1); + } + kd->vmst->PML4 = PML4; + return (0); +} + +static int +_amd64_vatop(kvm_t *kd, kvaddr_t va, off_t *pa) +{ + struct vmstate *vm; + amd64_physaddr_t offset; + amd64_physaddr_t pdpe_pa; + amd64_physaddr_t pde_pa; + amd64_physaddr_t pte_pa; + amd64_pml4e_t pml4e; + amd64_pdpe_t pdpe; + amd64_pde_t pde; + amd64_pte_t pte; + kvaddr_t pml4eindex; + kvaddr_t pdpeindex; + kvaddr_t pdeindex; + kvaddr_t pteindex; + amd64_physaddr_t a; + off_t ofs; + size_t s; + + vm = kd->vmst; + offset = va & AMD64_PAGE_MASK; + + /* + * If we are initializing (kernel page table descriptor pointer + * not yet set) then return pa == va to avoid infinite recursion. + */ + if (vm->PML4 == NULL) { + s = _kvm_pa2off(kd, va, pa); + if (s == 0) { + _kvm_err(kd, kd->program, + "_amd64_vatop: bootstrap data not in dump"); + goto invalid; + } else + return (AMD64_PAGE_SIZE - offset); + } + + pml4eindex = (va >> AMD64_PML4SHIFT) & (AMD64_NPML4EPG - 1); + pml4e = le64toh(vm->PML4[pml4eindex]); + if ((pml4e & AMD64_PG_V) == 0) { + _kvm_err(kd, kd->program, "_amd64_vatop: pml4e not valid"); + goto invalid; + } + + pdpeindex = (va >> AMD64_PDPSHIFT) & (AMD64_NPDPEPG - 1); + pdpe_pa = (pml4e & AMD64_PG_FRAME) + (pdpeindex * sizeof(amd64_pdpe_t)); + + s = _kvm_pa2off(kd, pdpe_pa, &ofs); + if (s < sizeof(pdpe)) { + _kvm_err(kd, kd->program, "_amd64_vatop: pdpe_pa not found"); + goto invalid; + } + if (pread(kd->pmfd, &pdpe, sizeof(pdpe), ofs) != sizeof(pdpe)) { + _kvm_syserr(kd, kd->program, "_amd64_vatop: read pdpe"); + goto invalid; + } + pdpe = le64toh(pdpe); + if ((pdpe & AMD64_PG_V) == 0) { + _kvm_err(kd, kd->program, "_amd64_vatop: pdpe not valid"); + goto invalid; + } + + if (pdpe & AMD64_PG_PS) { + /* + * No next-level page table; pdpe describes one 1GB page. + */ + a = (pdpe & AMD64_PG_1GB_FRAME) + (va & AMD64_PDPMASK); + s = _kvm_pa2off(kd, a, pa); + if (s == 0) { + _kvm_err(kd, kd->program, + "_amd64_vatop: 1GB page address not in dump"); + goto invalid; + } else + return (AMD64_NBPDP - (va & AMD64_PDPMASK)); + } + + pdeindex = (va >> AMD64_PDRSHIFT) & (AMD64_NPDEPG - 1); + pde_pa = (pdpe & AMD64_PG_FRAME) + (pdeindex * sizeof(amd64_pde_t)); + + s = _kvm_pa2off(kd, pde_pa, &ofs); + if (s < sizeof(pde)) { + _kvm_syserr(kd, kd->program, "_amd64_vatop: pde_pa not found"); + goto invalid; + } + if (pread(kd->pmfd, &pde, sizeof(pde), ofs) != sizeof(pde)) { + _kvm_syserr(kd, kd->program, "_amd64_vatop: read pde"); + goto invalid; + } + pde = le64toh(pde); + if ((pde & AMD64_PG_V) == 0) { + _kvm_err(kd, kd->program, "_amd64_vatop: pde not valid"); + goto invalid; + } + + if (pde & AMD64_PG_PS) { + /* + * No final-level page table; pde describes one 2MB page. + */ + a = (pde & AMD64_PG_PS_FRAME) + (va & AMD64_PDRMASK); + s = _kvm_pa2off(kd, a, pa); + if (s == 0) { + _kvm_err(kd, kd->program, + "_amd64_vatop: 2MB page address not in dump"); + goto invalid; + } else + return (AMD64_NBPDR - (va & AMD64_PDRMASK)); + } + + pteindex = (va >> AMD64_PAGE_SHIFT) & (AMD64_NPTEPG - 1); + pte_pa = (pde & AMD64_PG_FRAME) + (pteindex * sizeof(amd64_pte_t)); + + s = _kvm_pa2off(kd, pte_pa, &ofs); + if (s < sizeof(pte)) { + _kvm_err(kd, kd->program, "_amd64_vatop: pte_pa not found"); + goto invalid; + } + if (pread(kd->pmfd, &pte, sizeof(pte), ofs) != sizeof(pte)) { + _kvm_syserr(kd, kd->program, "_amd64_vatop: read"); + goto invalid; + } + if ((pte & AMD64_PG_V) == 0) { + _kvm_err(kd, kd->program, "_amd64_vatop: pte not valid"); + goto invalid; + } + + a = (pte & AMD64_PG_FRAME) + offset; + s = _kvm_pa2off(kd, a, pa); + if (s == 0) { + _kvm_err(kd, kd->program, "_amd64_vatop: address not in dump"); + goto invalid; + } else + return (AMD64_PAGE_SIZE - offset); + +invalid: + _kvm_err(kd, 0, "invalid address (0x%jx)", (uintmax_t)va); + return (0); +} + +static int +_amd64_kvatop(kvm_t *kd, kvaddr_t va, off_t *pa) +{ + + if (ISALIVE(kd)) { + _kvm_err(kd, 0, "kvm_kvatop called in live kernel!"); + return (0); + } + return (_amd64_vatop(kd, va, pa)); +} + +int +_amd64_native(kvm_t *kd __unused) +{ + +#ifdef __amd64__ + return (1); +#else + return (0); +#endif +} + +static struct kvm_arch kvm_amd64 = { + .ka_probe = _amd64_probe, + .ka_initvtop = _amd64_initvtop, + .ka_freevtop = _amd64_freevtop, + .ka_kvatop = _amd64_kvatop, + .ka_native = _amd64_native, +}; + +KVM_ARCH(kvm_amd64); |